The Gemara notes two competing customs on Yom Kippur, those who light candles and those who do not. Both customs are derived from the same purpose, which is either by omission or commission of light to remind couples that marital relations are forbidden on Yom Kippur.
The Ishbitzer in his Mei HaShiloach commentary (see Devarim 13 and Bereishis 7) quotes this Gemara to make philosophical point about the intentions and fulfillment of the mitzvos. The verse states (Devarim 6:17):
שָׁמ֣וֹר תִּשְׁמְר֔וּן אֶת־מִצְוֺ֖ת יְהוָ֣ה אֱלֹהֵיכֶ֑ם וְעֵדֹתָ֥יו וְחֻקָּ֖יו אֲשֶׁ֥ר צִוָּֽךְ׃
You (plural), be sure to keep the commandments, decrees, and laws and testimonies that the LORD your God has enjoined upon you (singular)..
It starts addressing the plural “Tishmerun”, abs ends with addressing a single person “tzivach”.
This connotes that the law and the obligation of every commandment remains static and unchanging. However the meaning and message in each commandment can be personal to each individual. That is why the second part of the verse which is singular refers to testimonies, because the mitzvos testify and speak to each person differently.
This is a key theological point that is meaningful especially in modern times when so much has changed, and many Jews struggle to find personal relevance to particular mitzvos that seem ancient. While we are uniformly bound by the halakha in the practical observance, we have permission to find new and personal relevance and meaning to each mitzvah as we perform it.
Translations Courtesy of Sefaria