Narrated 'Ikrima:

Ibn 'Abbas said, "Preach to the people once a week, and if you won't, then preach them twice, but if you want to preach more, then let it be three times (a week only), and do not make the people fed-up with this Qur'an. If you come to some people who are engaged in a talk, don't start interrupting their talk by preaching, lest you should cause them to be bored. You should rather keep quiet, and if they ask you, then preach to them at the time when they are eager to hear what you say. And avoid the use of rhymed prose in invocation for I noticed that Allah's Apostle and his companions always avoided it."

حَدَّثَنَا يَحْيَى بْنُ مُحَمَّدِ بْنِ السَّكَنِ، حَدَّثَنَا حَبَّانُ بْنُ هِلاَلٍ أَبُو حَبِيبٍ، حَدَّثَنَا هَارُونُ الْمُقْرِئُ، حَدَّثَنَا الزُّبَيْرُ بْنُ الْخِرِّيتِ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، قَالَ حَدِّثِ النَّاسَ، كُلَّ جُمُعَةٍ مَرَّةً، فَإِنْ أَبَيْتَ فَمَرَّتَيْنِ، فَإِنَّ أَكْثَرْتَ فَثَلاَثَ مِرَارٍ وَلاَ تُمِلَّ النَّاسَ هَذَا الْقُرْآنَ، وَلاَ أُلْفِيَنَّكَ تَأْتِي الْقَوْمَ وَهُمْ فِي حَدِيثٍ مِنْ حَدِيثِهِمْ فَتَقُصُّ عَلَيْهِمْ، فَتَقْطَعُ عَلَيْهِمْ حَدِيثَهُمْ فَتُمِلُّهُمْ، وَلَكِنْ أَنْصِتْ، فَإِذَا أَمَرُوكَ فَحَدِّثْهُمْ وَهُمْ يَشْتَهُونَهُ، فَانْظُرِ السَّجْعَ مِنَ الدُّعَاءِ فَاجْتَنِبْهُ، فَإِنِّي عَهِدْتُ رَسُولَ اللَّهِ ﷺ وَأَصْحَابَهُ لاَ يَفْعَلُونَ إِلاَّ ذَلِكَ. يَعْنِي لاَ يَفْعَلُونَ إِلاَّ ذَلِكَ الاِجْتِنَابَ.