Silence of the Fast

Leviticus 16:29-31 This is to be a lasting ordinance for you: On the tenth day of the seventh month you must deny yourselves and not do any work - whether native-born or an alien living among you, because on this day atonement will be made for you, to cleanse you. Then, before the LORD, you will be clean from all your sins. It is a sabbath of rest, and you must deny yourselves; it is a lasting ordinance.

2 Chronicles 7:8-10 So Solomon observed the festival at that time for seven days, and all Israel with him - a vast assembly, people from Lebo Hamath to the Wadi of Egypt. On the eighth day they held an assembly, for they had celebrated the dedication of the altar for seven days and the festival for seven days more. On the twenty-third day of the seventh month he sent the people to their homes, joyful and glad in heart for the good things the LORD had done for David and Solomon and for his people Israel.

Indeed, according to Leviticus 16:29-31, Israel was to fast and possibly even show further penitence by wearing sackcloth (Psa. 35:13). Failure to observe this day made one liable unto death (Lev. 23:28-30).

However, just because something is not mentioned in Scripture, does not mean it did not take place. We do similar things even today. For instance, on the day I wrote the answer to this question, this was a true statement: "I wrote the answer to this question today." However, though I do not mention it in the quote above, I also did several others things the same day - prayed, read, turned on the computer, ate, etc.

Now, returning to Leviticus 16:29-31 and Leviticus 23:28-30, we may observe the importance of the festival and the penalty accompanying its improper observance. In addition, in 2 Chronicles, we may also observe God's response to Solomon's dedication (2 Chron. 7:11-22). So, I believe the Bible reader may safely assume it was observed.

R.B. Dillard states:

The Chronicler appears to be elaborating on 1 Kgs 8:65 to clarify the precise sequence of events. The dedication festival lasted seven days, from the eighth to the fourteenth of the month, and was followed by the regular observance of the Feast of Tabernacles from the fifteenth to the twenty-second day of the month. The eighth day (7:9; cf. Lev 23:39) would be the final convocation on the twenty-second, followed by dismissal on the twenty-third day of the month (7:10). Again a parallel has been achieved with David who similarly dismissed a national assembly (1 Chr 16:13, 43). The celebration would have included the Day of Atonement (Lev 23:2632; Lev 16) on the tenth day, but the author is silent about it. A similar two-week observance of the temple dedications occurred under Hezekiah (30:23).

Reference

Dillard, R. B. Word Biblical Commentary Vol.15, 2 Chronicles. Dallas: Word, Incorporated, 2002.