What did God pour out at the cross when Christ died?
At the cross, when Christ died and took the wrath of God for the sins of the world, God poured out His wrath and also poured out His mercy. That mercy is already available, no longer something to beg for, and is appropriated by faith.
Les explains that mankind deserves absolutely nothing, yet God provided a way back to Himself because of His mercy. When Christ died on the cross, He took all the wrath of God for the sins of the world, and at that same cross God not only poured out His wrath but also poured out His mercy. Because that mercy has already been poured out, we no longer have to beg for it; it is all there, and all we have to do is appropriate it by faith. The surrounding context also notes that God had not forgotten the Gentiles, though He could not deal with them until Christ went to the cross.