John Gill Commentary Psalms 109:12

"Let there be none to extend kindness unto him; Neither let there be any to have pity on his fatherless children." — Psalms 109:12 (ASV)

Let there be none to extend mercy unto him
No pity is ever expressed at hearing or reading the sad case of Judas; and though the Jews were pitied of those that carried them captive to Babylon, (Psalms 106:46), yet, in their last destruction by the Romans, no mercy was shown them; the wrath of God and man came upon them to the uttermost, (1 Thessalonians 2:16) .

Neither let there be any to favour his fatherless children :
to bestow any benefit upon them; to relieve their wants, nor to protect their persons; no more respect shown them than to their father, being shunned and hated for their father's sake.