Silsilah as-Sahihah 508 — Prohibition of standing in prayer or fasting

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Do not single out the night of Friday for standing (in prayer), nor single out its day for fasting, unless a man is in the habit of fasting (and Friday happens to be his day to fast), then he may fast."