Bayhaqi 630 — Ablution (wudu) after touching the private part

It is narrated from Salim bin Abdullah (may Allah have mercy on him) that he said: I saw Abdullah bin Umar (may Allah be pleased with them both); he would first take a ritual bath and then perform ablution. I asked him: O my father, does the bath not suffice for ablution? He said: Of course it does, but sometimes I touch my private part, so I perform ablution.