People find joy and emotional uplift in two distinct ways, through the physical delights of the senses and through the deep connection of human relationships. King Solomon draws a profound parallel between the bodily enjoyment of pleasant fragrances and the mental and emotional satisfaction provided by true friendship.
Physical pleasures, such as fine oils and incense, arrive from the outside to bring joy to the heart. This includes the richness of anointing oils, the unique scent of persimmon, the pure light of an oil lamp, and fine foods [אבן עזרא, רש״י, עמנואל הרומי]. Similarly, the smoke of quality spices and woods purifies the air and provides a delightful aroma [מצודת ציון, עמנואל הרומי]. The primary approach among commentators is that these external scents and comforts naturally gladden a person. While breathing is a basic requirement for survival, inhaling a beautiful fragrance from the outside actively awakens the soul and grants it renewed strength [מלבי״ם]. On a conceptual level, oil symbolizes pure wisdom that rises above everything else, while incense fortifies the mind, which serves as the dwelling place of the soul [אמרי דעת].
In the exact same way that these fragrances invigorate the body, the sweetness of a friend uplifts the mind. This sweetness is found in shared secrets, meaningful conversations, and good advice [אבן עזרא, מלבי״ם].
The primary approach among commentators views this dynamic as the immense benefit of consulting others. Just as a pleasant scent comes from the outside to bring happiness, receiving warm, caring advice from a friend is far more valuable than a person relying entirely on their own judgment [רש״י, רלב״ג, עמנואל הרומי]. When the external guidance of a companion merges with a person's internal thoughts, the resulting decision becomes complete and effective [מלבי״ם].
Another perspective emphasizes the honesty and depth of true companionship. The sweetness lies in the fact that the friend speaks from the very depths of their soul, driven by genuine love and sincerity rather than flattery or deceit [מצודת דוד, ביאור שטיינזלץ]. This reflects a bond where friends can retreat together to pursue wisdom, share secrets, and discuss matters of the spirit [אמרי דעת]. On a spiritual and moral level, a true friend is one who guides someone to act in ways that are pleasing to God, which is ultimately more beneficial than simply chasing personal desires [רש״י].
Taking this to a deeper, symbolic level, the fragrant oils and incense hint at the ultimate spiritual pleasures of the World to Come and the Garden of Eden. In this hidden view, the companion of the soul is actually the physical body. In the future, the physical body will also merit experiencing this ultimate sweetness, entirely as a result of the constant guidance and counsel that the soul provided it throughout its life [אלשיך].