Adam Clarke on Luke 2:45

Seeking him - Ζητουντες αυτον - or rather, seeking him diligently, αναζητουντες. This is the reading of BCDL, six others, Vulgate, and nine copies of the Itala. If they sought earnestly when they first found him missing, there is little doubt that their solicitude and diligence must be greatly increased during his three days' absence, therefore the word which I have adopted, on the above authority, is more likely to be the true reading than the ζητουντες of the common text, which simply signifies seeking; whereas the other strongly marks their solicitude and diligence.