Srimad Bhagavatam Canto 11, Chapter 18, Text 03

SB 11.18.3

kesa-roma-nakha-smasru-
 malani bibhryad datah
na dhaved apsu majjeta
 tri kalam sthandile-sayah
 
Translation: 
 
The vanaprastha should not groom the hair on his head, body or face, should not manicure his nails, should not pass stool and urine at irregular times and should not make a special endeavor for dental hygiene. He should be content to take bath in water three times daily and should sleep on the ground.
Srimad Bhagavatam Canto 11, Chapter 18, Text 02
Srimad Bhagavatam Canto 11, Chapter 18, Text 04