Special cow?
There was a nun whose old body began to surrender to time. Her doctor prescribed for her a shot of whiskey three times a day to relax her. Not to be lured into "worldly pleasures", she huffily declined.
But the Mother Superior knew the elderly sister loved milk. So she instructed the kitchen to spike the milk three times a day.
After a few more years, even that spiked milk couldn't help and the aged sister approached her final hour. As several nuns gathered around her at her bedside, the Mother Superior asked if she wanted to leave them with any words of wisdom.
"Oh, yes," she replied. "Never sell that cow!"