The 63-year-old momager has confirmed what many Kim Kardashian and Kanye West fans had speculated in that their fourth child's moniker, which also means "sacred song or hymn", was inspired by the Christian Old Testament.
She said: "The inspiration was the 'Book of Psalms' in the Bible."
Kris also admitted the youngster has been "such a blessing" for the showbiz power couple, and described him as "perfect".
Speaking to 'Entertainment Tonight', she added: "I think it's just a wonderful way to celebrate how they feel. And he's such a blessing, so it's perfect."
Kris' name inspiration confirmation comes after it was said the couple had "mutually" agreed on the moniker, and that rapper Kanye was "very involved" in the process, as a regular reader of 'Psalms', the third section of the Hebrew Bible.
A source said: "He and Kim do exactly what every couple does, where they each bring up names and the other one gives their feedback.
"It's very traditional that way.
"Kanye would never just choose a name that Kim doesn't like, or vice versa. The names are things that they mutually agree upon."
Psalm was born via surrogate just two weeks ago, and Kim and Kanye - who also have kids North, five, Saint, three, and 16-month-old Chicago - are said to be "bursting with happiness" over the new arrival.
A source recently said: "Kim and Kanye are bursting with happiness over Psalm. He's such an incredibly great baby, and so far, it's been an easy addition to the family...
"Kim and Kanye are both busy with their projects, but have slowed down a bit recently to spend quality time with Psalm."
"The kids instantly fell in love with him. North will always be the one in charge, but she loves her little brother."