Hebrews 5:13

For every one that useth milk is unskilful in the word of righteousness: for he is a babe.
— Hebrews 5:13, King James Version

In other translations

World English Bible (WEB)

For everyone who lives on milk is not experienced in the word of righteousness, for he is a baby.

American Standard Version (ASV)

For every one that partaketh of milk is without experience of the word of righteousness; for he is a babe.

Young's Literal Translation (YLT)

for every one who is partaking of milk <FI>is<Fi> unskilled in the word of righteousness--for he is an infant,