The answer is: Yeast and honey

Lev 2:11 - Yeast and honey were prohibited in grain offerings to symbolize purity and absence of corruption.

In the ritual traditions outlined in Leviticus, grain offerings held a significant place, representing gratitude for the harvest and service to God. However, certain ingredients were deemed unsuitable – notably yeast and honey. This prohibition isn’t just about what’s ‘on the menu’; it's rich with meaning.

Yeast is often associated with fermentation. In a spiritual context, it's about how things can become corrupt and inflate beyond their natural state, thereby symbolizing moral deterioration. Similarly, honey, while sweet and pleasing to the palate, brings an image of something overindulgent, potentially distractive from the primary devotion. Just think: every time we encounter a reference to unleavened bread—the usual fare in rituals—it's all about that focus on steadfastness and simplicity. It connects back to the Passover and the Israelites’ hasty exodus; no time for leavening breads!

In essence, these restrictions teach us about the values of spirituality that favor purity and simplicity. They also invite us to consider what our own 'offerings' are in daily life—how do we make sure we’re accessible and genuine, avoiding complications that could muddy the waters of our intentions? This ruler of restraint echoes throughout history in various spiritual practices, fostering the theme that sometimes less truly is more!