Abdullah bin Jafar bin Abu Talib reported,

The Messenger of Allah ﷺ once seated me behind him on his mount and confided to me something I would never share with anyone. The places the Messenger of Allah ﷺ most preferred to use as cover when relieving himself were a raised barrier or a cluster of palm trees.In another narration he said, meaning a palm grove.

Azami 1397

Sahih

عن عبد الله بن جعفر قال

أردفني رسول الله ﷺ ذات يوم خلفه، فأسر إلى حديثا لا أحدث به أحدا من الناس، وكان أحب ما استتر به رسول الله ﷺ لحاجته هدف، أو حائش نخل. وقال في رواية: يعني حائط نخل.

الأعظمي 1397صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Purification
Section
Concealment when relieving oneself
Numbering
Jami al-Kamil 1397 (2nd edition)
Azami 1397