I do not presume to say what this cup is, nor to what the whole allusion is designed: perhaps it means a mixture of what God's people are appointed to drink in soul exercises, and in providences. And perhaps it means that the people of God shall drink of the blood of the Lamb. But one thing I beg to remark, that Jesus, when he came forth as the sinner's Surety, drank of the cup of trembling to the dregs, while his people have given to them the cup of salvation, that they may call upon the name of the Lord. Sweet is that precious scripture to this point, Isaiah 51:22-23; John 18:11.
Related Commentaries of Psalms 75:8
Psalms 75:8
8 For in the hand of the LORD there is a cup, and the wine is red; it is full of mixture; and he poureth out of the same: but the dregs thereof, all the wicked of the earth shall wring them out, and drink them.