Narrated Usayd ibn Hudayr,:
AbdurRahman ibn AbuLayla,
quoting Usayd ibn Hudayr, a man of the Ansar, said that while he was given to jesting and was talking to the people and making them laugh,
the Prophet (ﷺ) poked him under the ribs with a stick.
He said: Let me take retaliation.
He(ﷺ) said: Take retaliation.
He said: You are wearing a shirt but I am not.
The Prophet (ﷺ) then raised his shirt and the man (Usayd bin Hudayr) embraced him and began to kiss his side.
Then he said: This is what I wanted, Messenger of Allah!
(Sunan Abu Dawud,5224, Sahih Al-Albani)
It says in ‘Awn al-Ma‘bood (14/90):
“the Prophet (blessings and peace of Allah be upon him) poked him in the ribs with a stick” i.e., he struck him by way of joking and playing. “He” i.e., Usayd “said: Let me retaliate” i.e., allow me to poke you in the ribs as you poked me in the ribs. “Retaliate”i.e., take your revenge.
“and kissed his side” – the Arabic word translated as “side” refers to the area on the side of the body between the lowest rib and the hip.
“He said: This is all I wanted” that is, all I wanted by saying let me retaliate was to kiss you, and I did not really want to retaliate. End quote.
Saheehus-Seerah 