Ibn Abbas reported: A woman lifted up her child and said, “O Messenger of Allah, is the Hajj pilgrimage for this child?” The Prophet, peace and blessings be upon him, said, “Yes, you will have a reward.”
Source: Ṣaḥīḥ Muslim 1336
Grade: Sahih (authentic) according to Muslim
عَنْ ابْنِ عَبَّاسٍ قَالَ رَفَعَتْ امْرَأَةٌ صَبِيًّا لَهَا فَقَالَتْ يَا رَسُولَ اللَّهِ أَلِهَذَا حَجٌّ قَالَ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ نَعَمْ وَلَكِ أَجْرٌ
1336 صحيح مسلم كتاب الحج باب صحة حج الصبي وأجر من حج به