Aboo Sa'eed al Khudree (radhiyallaahu 'anh) narrated:
The Messenger of
Allaah (sallal Laahu 'alayhi wassallam) said:
"When a man wakes his wife in the
night and they both observe two rak'aat together, they would be counted among
those who remember Allah a lot"
- Saheeh Abee Daawud #1181, #1182.