Sunan an-Nasa'i, Volume 3, Book 23, Hadith 2588 (DarusSalam) ⓘ
It was narrated from Ibn Al-Firasi that Al-Firasi said to the Messenger of Allah: "Shall I ask people (for help), O Messenger of Allah?" He said: "No, but if you have no alternative but to ask, then ask the righteous."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ جَعْفَرِ بْنِ رَبِيعَةَ، عَنْ بَكْرِ بْنِ سَوَادَةَ، عَنْ مُسْلِمِ بْنِ مَخْشِيٍّ، عَنِ ابْنِ الْفِرَاسِيِّ، أَنَّ الْفِرَاسِيَّ، قَالَ لِرَسُولِ اللَّهِ صلى الله عليه وسلم أَسْأَلُ يَا رَسُولَ اللَّهِ قَالَ " لاَ وَإِنْ كُنْتَ سَائِلاً لاَ بُدَّ فَاسْأَلِ الصَّالِحِينَ " .
also referenced under: Hadith 2587 (Reference) & Book 23, Hadith 0 (In-Book)