Verses with the word doubtless in the Old Testament (4 verses):
Doubtless ye shall not come into the land, concerning which I sware to make you dwell therein, save Caleb the son of Jephunneh, and Joshua the son of Nun.
2 Samuel 5:19
And David enquired of the LORD, saying, Shall I go up to the Philistines? wilt thou deliver them into mine hand? And the LORD said unto David, Go up: for I will doubtless deliver the Philistines into thine hand.
He that goeth forth and weepeth, bearing precious seed, shall doubtless come again with rejoicing, bringing his sheaves with him.
Doubtless thou art our father, though Abraham be ignorant of us, and Israel acknowledge us not: thou, O LORD, art our father, our redeemer; thy name is from everlasting.