Narrated Bahz bin Hakim on his father's authority from his grandfather (RA):

I asked, "O Allah's Messenger (ﷺ) , to whom should I be kind and dutiful?" He replied, "Your mother." I asked, "Who comes next?" He replied, "Your mother." I asked, "Who comes next?" He replied, "Your mother." I asked, "Who comes next?" He replied, "Your father, then your relatives in order of nearness (of relationship)." [Abu Dawud and at-Tirmidhi reported it; the latter graded it Hasan (good)].

وَعَنْ بَهْزِ بْنِ حَكِيمٍ, عَنْ أَبِيهِ, عَنْ جَدِّهِ قَالَ: { قُلْتُ: يَا رَسُولَ اَللَّهِ! مَنْ أَبَرُّ? قَالَ: "أُمَّكَ".‏ قُلْتُ: ثُمَّ مِنْ? قَالَ: "أُمَّكَ".‏ قُلْتُ: ثُمَّ مِنْ "? قَالَ: "أُمَّكَ".‏ قُلْتُ: ثُمَّ مِنْ? قَالَ: "أَبَاكَ, ثُمَّ اَلْأَقْرَبَ فَالْأَقْرَبَ".‏ } أَخْرَجَهُ أَبُو دَاوُدَ, وَاَلتِّرْمِذِيُّ وَحُسَّنَهُ [1]‏ .‏