Albert Barnes Commentary 1 Kings 7:18

"So he made the pillars; and there were two rows round about upon the one network, to cover the capitals that were upon the top of the pillars: and so did he for the other capital." — 1 Kings 7:18 (ASV)

The pomegranate was one of the most common ornaments in Assyria. It was used on quivers, spear-shafts, and mace-heads, and in patterns on doorways and pavements. It is doubtful whether a symbolic meaning was attached to it, or if it was merely selected as a beautiful natural form.