Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bayhaqi:21187al-Ḥasan b. Sufyān > Abū Bakr > Ḥumayd b. ʿAbd al-Raḥman > Ḥasan > Layth > ʿAṭāʾ And Ṭāws

[Machine] "Ata and Tawus said: It is not permissible to have a testimony upon another testimony in a legal punishment (Hadd). We were narrated from Ash-Sha'bi and Ibrahim regarding the prevention of doubts in determining legal punishments in the Book of Hadd."  

البيهقي:٢١١٨٧قَالَ وَحَدَّثَنَا الْحَسَنُ بْنُ سُفْيَانَ ثنا أَبُو بَكْرٍ ثنا حُمَيْدُ بْنُ عَبْدِ الرَّحْمَنِ عَنْ حَسَنٍ عَنْ لَيْثٍ

عَنْ عَطَاءٍ وَطَاوُسٍ قَالَا لَا تَجُوزُ شَهَادَةٌ عَلَى شَهَادَةٍ فِي حَدٍّ وَرُوِّينَا عَنِ الشَّعْبِيِّ وَإِبْرَاهِيمَ وَقَدْ مَضَتِ الْأَخْبَارُ فِيهِ فِي دَرْءِ الْحُدُودِ بِالشُّبُهَاتِ فِي كِتَابِ الْحُدُودِ