John Gill Commentary Psalms 109:14

"Let the iniquity of his fathers be remembered with Jehovah; And let not the sin of his mother be blotted out." — Psalms 109:14 (ASV)

Let the iniquity of his fathers be remembered with the Lord ,
&c.] Not of Abraham, Isaac, and Jacob; who, though they had their failings, they were not remembered, and much less punished in their posterity, but were forgiven: rather of the Amorites and Hittites; the one being said to be the father, and the other the mother, of the Jews, (Ezekiel 16:3) , they succeeding them in their land, and imitating their example, and committing the same sins they did: or rather of their wicked ancestors, who killed the prophets; and the measure of whose sins Judas and the Jews filled up in crucifying Christ, see (Matthew 23:31Matthew 23:32) . The iniquity of these may be said to be remembered, it not being forgiven, when it was brought to account, and punished in their posterity, doing the same wicked actions; compare with this (Revelation 16:19) (18:5) .

And let not the sin of his mother be blotted out :
or forgiven; but stand as a debt to be accounted for: meaning not the sin of his mother Eve, nor of his immediate parent; but either of the Hittite as before, or of the synagogue of the Jews, or Jerusalem, which killed the prophets of the Lord.