Leaving some milk when milking an animal

[AI] He said: My family sent me with a milch-camel - and Abu Muawiyah said: with a milch she-camel - to the Prophet ﷺ. I brought it to him, and he ordered me to milk it. Then he said, "Leave some milk behind." Abu Muawiyah said: Do not exhaust her.

قَالَ: بَعَثَنِي أَهْلِي بِلَقُوحٍ، وَقَالَ أَبُو مُعَاوِيَةَ: بِلَقْحَةٍ، إِلَى النَّبِيِّ ﷺ، فَأَتَيْتُهُ بِهَا، فَأَمَرَنِي أَنْ أَحْلُبَهَا، ثُمَّ قَالَ: «دَعْ دَاعِيَ اللَّبَنِ». قَالَ أَبُو مُعَاوِيَةَ: لَا تُجْهِدَنَّهَا.