1
general::
Phrase(s): Take it from me!
Inf. Believe me! • It’s true! Take it from me! • Take it from me. This is a very good day for this part of the country.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Also, you can take it from me. Rest assured, believe me, as in You can take it from me, we've been working hard on it. This idiom was first recorded in 1622 in slightly different form, take it upon my word. The current form appeared in 1672.
American Heritage Idioms