Judamat al-Asadiyyah said that she heard the Messenger of Allah ﷺ Say:
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.

حَدَّثَنَا الْقَعْنَبِيُّ، عَنْ مَالِكٍ، عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ نَوْفَلٍ، أَخْبَرَنِي عُرْوَةُ بْنُ الزُّبَيْرِ، عَنْ عَائِشَةَ، زَوْجِ النَّبِيِّ ﷺ عَنْ جُدَامَةَ الأَسَدِيَّةِ أَنَّهَا سَمِعَتْ رَسُولَ اللَّهِ ﷺ يَقُولُ " لَقَدْ هَمَمْتُ أَنْ أَنْهَى عَنِ الْغَيْلَةِ حَتَّى ذُكِّرْتُ أَنَّ الرُّومَ وَفَارِسَ يَفْعَلُونَ ذَلِكَ فَلاَ يَضُرُّ أَوْلاَدَهُمْ " . قَالَ مَالِكٌ الْغَيْلَةُ أَنْ يَمَسَّ الرَّجُلُ امْرَأَتَهُ وَهِيَ تُرْضِعُ .