The omnipotent Yamaraja is as good as Lord Brahma for while situated in his own abode or in everyone's heart like the Paramatma, he mentally observes the past activities of a living entity & thus understands how the living entity will act in future lives

Expressions researched:
"The omnipotent Yamarāja is as good as Lord Brahmā, for while situated in his own abode or in everyone's heart like the Paramātmā, he mentally observes the past activities of a living entity and thus understands how the living entity will act in future lives"

Srimad-Bhagavatam

SB Canto 6

The omnipotent Yamarāja is as good as Lord Brahmā, for while situated in his own abode or in everyone's heart like the Paramātmā, he mentally observes the past activities of a living entity and thus understands how the living entity will act in future lives.

SB 6.1.48, Translation and Purport

The omnipotent Yamarāja is as good as Lord Brahmā, for while situated in his own abode or in everyone's heart like the Paramātmā, he mentally observes the past activities of a living entity and thus understands how the living entity will act in future lives.

One should not consider Yamarāja an ordinary living being. He is as good as Lord Brahmā. He has the complete cooperation of the Supreme Lord, who is situated in everyone's heart, and therefore, by the grace of the Supersoul, he can see the past, present and future of a living being from within. The word anumīmāṁsate means that he can decide in consultation with the Supersoul. Anu means "following." The actual decisions concerning the next lives of the living entities are made by the Supersoul, and they are carried out by Yamarāja.