The Prophet (peace and blessings of Allaah be upon him) said:
“Three prayers are undoubtedly answered:
1. The prayer of one who is wronged,
2. The prayer of the traveller and
3. The prayer of a father for his child.”
Narrated by Ibn Maajah (3862); classed as saheeh (authentic) by al-Albaani in Silsilat al-Ahaadeeth al-Saheehah (596).