When you are afraid of being left with no one
Zakariyyā ﷺ, old and without a child, asking not to be left alone.
وَزَكَرِيَّآ إِذْ نَادَىٰ رَبَّهُۥ رَبِّ لَا تَذَرْنِى فَرْدًا وَأَنتَ خَيْرُ ٱلْوَٰرِثِينَ
Rabbi lā tadharnī fardan wa anta khayru-l-wārithīn.
And [mention] Zechariah, when he called to his Lord, "My Lord, do not leave me alone [with no heir], while You are the best of inheritors."
He adds the second half himself: even if no one is left, You remain. The asking and the acceptance sit in one sentence.
Source
The Qur'an · 21:89
Qur'an
- Qur'anic text in the Uthmani script via Quran.com; translation: Saheeh International