Hadith 151B3

وَسُئِلَ مَالِك ، عَنْ قَوْمٍ حُضُورٍ أَرَادُوا أَنْ يَجْمَعُوا الْمَكْتُوبَةَ فَأَرَادُوا أَنْ يُقِيمُوا وَلَا يُؤَذِّنُوا ، قَالَ مَالِك: ذَلِكَ مُجْزِئٌ عَنْهُمْ ، وَإِنَّمَا يَجِبُ النِّدَاءُ فِي مَسَاجِدِ الْجَمَاعَاتِ الَّتِي تُجْمَعُ فِيهَا الصَّلَاةُ .
Imam Malik (may Allah have mercy on him) was asked: If a few resident people intend to perform the obligatory prayer in congregation, is it sufficient to only say the iqamah (takbir), or is giving the adhan also necessary? Imam Malik (may Allah have mercy on him) replied: Saying the iqamah (takbir) is sufficient. And the adhan is obligatory in those mosques where prayer is performed in congregation.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب الصلاة / 151B3
Hadith Takhrij «شركة الحروف نمبر: 140، فواد عبدالباقي نمبر: 3 - كِتَابُ الصَّلَاةِ-ح: 7»