It was narrated from Ibn 'Umar and 'Aishah that the Messenger of Allah (ﷺ) said:
"Whoever demands his rights let him do so in a decent manner as much as he can." (DE)
English reference (DE): Vol. 3, Book 15, Hadith 2421 (DE)
Arabic reference (DE): Book 15, Hadith 2515 (DE)