There are very complicated reasons for my answer, but he should have AA- QQ, or a hand that has no equity at all in the pot like J,2 offsuit or 9, 3 offsuit.
Ironically it doesnt matter because the appropriate thing to do is fold either way. If he has AA-QQ you are dead, and if he has a hand with no pot equity, you will be getting no impied odds
to call, because you will not get a dime on or after the flop.
His bet indicates that for you to make an equitable call, presuming he is astute and believes you are also, then his bet was actually a work of art. Higher pockets and you would push, so if you just call he knows you have low pockets, which means he can out play the flop.
The reason for why he could be playing garbage there is to balance strategy for when he does get a big hand in the big blind. It wouldnt be his first time making a raise from the BB, and likely to receive action.
See raising from the blind generally doesnt get any action, so if you do it once or twice, you can player larger hands stealthily from those positions later. By balancing in this way, folks will put you on the above. garbage or AA-QQ.
This is very advanced level poker, and I dont give most credit for this level of meta game play. Therefor he probably had AA-QQ. Regardless fold.
I like his play and hope you folded. I probably add him to a beware list, and see if his play warrants more scrutiny.
Did this all make sense?