"They said, 'By Allah!'" This is an oath. "'You will not cease remembering Yusuf,'" Qatada said: meaning, you will not stop remembering Yusuf, "'until you become haradan'" that is, until you wither away, "'or until you become of the dead'" that is, until you die.
Muhammad said: It is said: "Grief has 'ahradahu' (consumed him)" when it wears him out.
﴿قَالُوا تالله﴾ قسمٌ ﴿تفتأ تذكر يُوسُف﴾ قَالَ قَتَادَةُ: يَعْنِي لَا تَزَالُ تَذْكُرُ يُوسُفَ ﴿حَتَّى تَكُونَ حرضا﴾ أَيْ: تَبْلَى ﴿أَوْ تَكُونَ مِنَ الهالكين﴾ أَيْ: تَمُوتَ.
قَالَ محمدٌ: يُقَالُ: أحرضه الْحزن إِذا أدقعه.