Sahih Muslim Book 25, Hadith Number 5348.

Chapter : The Excellence of Tahnik of the new-born child at the time of its birth and of carrying it to a pious person so that he may soften some dates and rub its palate with them, and permissibility of giving name on the day of its birth and the excellence of such names as ‘Abdullah, Ibrahim and the names of all the apostles of Allah (may peace be upon him).

‘Aisha reported: We took ‘Abdullah b. Zubair to Allah’s Apostle (may peace be upon him) so that he should put saliva in his mouth and we had to make a good deal of effort in order to procure them.