Divrey Hayamim Alef 28:9

And thou, Sh'lomo beni (my son), know thou the Elohei Avicha, and serve Him with a lev shalem and with a nefesh chafetzah (willing mind), for HASHEM searcheth kol levavot, and understandeth all the yetzer machashavot. If thou seek Him, He will be found by thee; but if thou forsake Him, He will cast thee off forever.