Can my 4 month old have a few small tastes of baby food on his tounge?

I have a son who was born 10 lbs 14 oz. He will be 4 months on Dec. 27th (which will be around the time I'd hope to give him a taste or two of gerber baby foods.) He doesn't have to eat the whole jar, nor even a few spoons full I'm only wondering if its safe at this month to introduce him to different tastes by letting him have an occasional taste through out the day. He is constantly eating his hands, and has been for the past month and a half. We don't know if this is teething or if he is hungry, or just enjoys doing it for fun! He is fed, and that is all he eats right now on demand.