1 Samuel 17 39
David strapped his sword on over the armor but he couldn't walk because he wasn't used to it. “I can't walk in all this,” David told Saul. “I ‘m not used to it.” So David took all the armor off.
Compare with other 3 random translations
YLT 1 Samuel 17:39And David girded his sword above his long robe, and beginneth to go, for he hath not tried it; and David saith unto Saul, 'I am not able to go with these, for I had not tried;' and David turneth them aside from off him.
ASV 1 Samuel 17:39And David girded his sword upon his apparel, and he assayed to go; for he had not proved it. And David said unto Saul, I cannot go with these; for I have not proved them. And David put them off him.
NAS 1 Samuel 17:39And David strapped on his sword over his military attire and struggled at walking, for he had not trained with the armor. So David said to Saul, “I cannot go with these, because I have not trained with them.” And David took them off.