The argument in Numbers is very similar.
Numbers 14:11-16 11 And the LORD said to Moses, “How long will this people spurn me? How long will they refuse to believe in me, despite all the signs I have performed among them? I will strike them with pestilence and wipe them out. Then I will make of you a nation greater and mightier than they.” But Moses said to the LORD: "Are the Egyptians to hear of this? For by your power you brought out this people from among them. And are they to tell of it to the inhabitants of this land? It has been heard that you, O LORD, are in the midst of this people; you, LORD, who plainly reveal yourself! Your cloud stands over them, and you go before them by day in a column of cloud and by night in a column of fire. If now you slay this whole people, the nations who have heard such reports of you will say, 'The LORD was not able to bring this people into the land he swore to give them; that is why he slaughtered them in the desert.'Now then, let the power of my Lord be displayed in its greatness, even as you have said, ‘The LORD is slow to anger and rich in kindness, forgiving wickedness and crime; yet not declaring the guilty guiltless, but punishing children to the third and fourth generation for their fathers’ wickedness.’ Pardon, then, the wickedness of this people in keeping with your great kindness, even as you have forgiven them from Egypt until now." The LORD answered: "I pardon them as you have asked.
This is a very similar situation. The Lord acts to save the reputation of his holy name with reguard to the nations, but note the content of that reputation as stated by Moses. “Pardon the wickedness in keeping with your great kindness…even as you have forgiven them from Egypt until now.” In this situation, it is not an arbitrary act to preserve the honour of his name, but to show him as a merciful forgiving God, capable of saving his people. This is what the glory of his name consists of. Showing himself as merciful, kind, and forgiving. Yes he punishes, but he does so only to save and reform.
When you say the following:
This is one of the key texts for Calvanism, for it seems to state clearly that God saves for no reason other than His own glory, rather than out of Love for His people and the desire for their happiness.
I would counter with what I quoted out of Numbers that the very glory of God is to show love for his people and a desire for their happiness. I don’t understand that Calvinistic concept of God because it does not square with any understanding of love that I’ve heard of. Doesn’t the Gosepls say God is Love?
I also think the passage is refering to the new covenant. A prophetic forshadowing of the covenant of Christ. The surrounding passages seem to support this:
Ezekiel 34:22-27 I will save my sheep so that they may no longer be despoiled, and I will judge between one sheep and another. I will appoint one shepherd over them to pasture them, my servant David; he shall pasture them and be their shepherd. I, the LORD, will be their God, and my servant David shall be prince among them. I, the LORD, have spoken. **I will make a covenant of peace with them, **and rid the country of ravenous beasts, that they may dwell securely in the desert and sleep in the forests. I will place them about my hill, sending rain in due season, rains that shall be a blessing to them. The trees of the field shall bear their fruits, and the land its crops, and they shall dwell securely on their own soil. Thus they shall know that I am the LORD when I break the bonds of their yoke and free them from the power of those who enslaved them. They shall no longer be despoiled by the nations or devoured by beasts of the earth, but shall dwell secure, with no one to frighten them. I will prepare for them peaceful fields for planting; they shall no longer be carried off by famine in the land, or bear the reproaches of the nations. Thus they shall know that I, the LORD, am their God, and they are my people, the house of Israel, says the Lord GOD. (You, my sheep, you are the sheep of my pasture, and I am your God, says the Lord GOD.)
Ezekiel 37:23-28 No longer shall they defile themselves with their idols, their abominations, and all their transgressions. I will deliver them from all their sins of apostasy, and cleanse them so that they may be my people and I may be their God. My servant David shall be prince over them, and there shall be one shepherd for them all; they shall live by my statutes and carefully observe my decrees. They shall live on the land which I gave to my servant Jacob, the land where their fathers lived; they shall live on it forever, they, and their children, and their children’s children, with my servant David their prince forever. I will make with them a covenant of peace; it shall be an everlasting covenant with them, and I will multiply them, and put my sanctuary among them forever. My dwelling shall be with them; I will be their God, and they shall be my people. Thus the nations shall know that it is I, the LORD, who make Israel holy, when my sanctuary shall be set up among them forever.
If I take anything from this passage, it is that God’s love is greater than human wickedness. It is not capricious or arbitrary, but constantly offered to an unworthy and sinful people, to the point of dying on a cross, the very sacrifice for sins that brings about this new covenant of peace. Do the people merit this love, do they deserve it? Absolutely not. It is a free gift from God that shows his justice and his mercy. A justice that turns on itself for the sake of God`s mercy.