Reference : Hisn al-Muslim 8

اِلبَـس جَديـداً
وَعِـشْ حَمـيداً
وَمُـتْ شهيداً
Ilbas jadīdan,
 wa `ish ḥamīdan, 
wa mut shahīdan.

Put on new clothes,
live a praise-worthy life 
and die as a martyr.

Reference:
Ibn Majah 2/1178, Al-Baghawi 12/41. See also Al-Albani, Sahih Ibn Majah 
2/275

Chapter: To someone wearing a new garment