I intended to prohibit suckling during pregnancy (ghailah), but I considered the Greeks and the Persians and saw that they practiced it, without any injury being caused to their children thereby. Malik said : Ghailah means that a man has intercourse with a women while she is suckling a child. (Using translation from Abū Dāʾūd 3882)

أَنَّهَا سَمِعَتْ رَسُولَ اللَّهِ ﷺ يَقُولُ «لَقَدْ هَمَمْتُ أَنْ أَنْهَى عَنِ الْغِيلَةِ حَتَّى ذَكَرْتُ أَنَّ الرُّومَ وَفَارِسَ يَصْنَعُونَ ذَلِكَ فَلَا يَضُرُّ أَوْلَادَهُمْ» قَالَ مَالِكٌ وَالْغِيلَةُ أَنْ يَمَسَّ الرَّجُلُ امْرَأَتَهُ وَهِيَ تُرْضِعُ