He who visits a diviner ('Arraf) and asks him about anything, his prayers extending to forty nights will not be accepted. (Using translation from Muslim 2230)   

عَنْ بَعْضِ أَزْوَاجِ النَّبِيِّ ﷺ عَنِ النَّبِيِّ ﷺ قَالَ مَنْ أَتَى عَرَّافًا فَصَدَّقَهُ بِمَا يَقُولُ لَمْ تُقْبَلْ لَهُ صَلَاةٌ أَرْبَعِينَ يَوْمًا